Foundation Alternatives for Ground Mount Solar Panel Installations

Expanding development of ground mount solar energy systems requires economic foundation systems that can support expected loads safely. The critical design loading for most ground mount solar systems in uplift from wind loading, especially for elevated systems that are designed to allow dual use of the land. A number of different types of foundations may be used to support the structural framework and resist uplift loading. Full-scale uplift tests taken to failure were performed on different foundations at five sites representing a range of soil conditions to illustrate the typical load capacity that can be achieved. The foundations included drilled piers, precast pedestals, driven steel H-piles, driven steel pipe piles and helical screw-piles. The results of load tests are presented along with a discussion of the potential advantages and limitations of the various types of foundations.